yacc `-Wconflicts-sr` and `-Wconflicts-srr` warnings

[crobinso]

Build on f43 has these yacc warnings:

...
index-parse.y: warning: 2 shift/reduce conflicts [-Wconflicts-sr]
index-parse.y: warning: 2 reduce/reduce conflicts [-Wconflicts-rr]
index-parse.y: note: rerun with option '-Wcounterexamples' to generate conflict counterexamples
...
updating index-parse.h
/usr/bin/make  all-am
  LEX      index-scan.c

Running with -Wcounterexamples gives this output. I have not attempted to make sense of it, so I'm just documenting it here

/home/crobinso/src/guestfs-tools/builder/index-parse.y: warning: 2 shift/reduce conflicts [-Wconflicts-sr]
/home/crobinso/src/guestfs-tools/builder/index-parse.y: warning: 2 reduce/reduce conflicts [-Wconflicts-rr]
/home/crobinso/src/guestfs-tools/builder/index-parse.y: warning: shift/reduce conflict on token EMPTY_LINE [-Wcounterexamples]
  First example: emptylines section EMPTY_LINE • EMPTY_LINE emptylines emptylines sections $end
  Shift derivation
    $accept
    ↳ 0: index                                                                                           $end
         ↳ 1: sections
              ↳ 4: emptylines section emptylines                                     emptylines sections
                                      ↳ 13: EMPTY_LINE emptylines
                                                       ↳ 13: • EMPTY_LINE emptylines
  Second example: emptylines section EMPTY_LINE EMPTY_LINE • EMPTY_LINE emptylines section emptylines $end
  Reduce derivation
    $accept
    ↳ 0: index                                                                                                                   $end
         ↳ 1: sections
              ↳ 4: emptylines section EMPTY_LINE emptylines                  sections
                                                 ↳ 13: EMPTY_LINE emptylines ↳ 3: emptylines                  section emptylines
                                                                  ↳ 12: ε •       ↳ 13: EMPTY_LINE emptylines
/home/crobinso/src/guestfs-tools/builder/index-parse.y: warning: shift/reduce conflict on token EMPTY_LINE [-Wcounterexamples]
  Example: emptylines section EMPTY_LINE • EMPTY_LINE emptylines section
  Shift derivation
    sections
    ↳ 4: emptylines section EMPTY_LINE emptylines                    sections
                                       ↳ 13: • EMPTY_LINE emptylines ↳ 3: emptylines section emptylines
                                                          ↳ 13: ε                            ↳ 3: ε
  Reduce derivation
    sections
    ↳ 4: emptylines section EMPTY_LINE emptylines sections
                                       ↳ 12: ε •  ↳ 3: emptylines                  section emptylines
                                                       ↳ 13: EMPTY_LINE emptylines         ↳ 3: ε
/home/crobinso/src/guestfs-tools/builder/index-parse.y: warning: reduce/reduce conflict on tokens $end, PGP_EPILOGUE [-Wcounterexamples]
  Example: emptylines section EMPTY_LINE emptylines •
  First reduce derivation
    sections
    ↳ 4: emptylines section EMPTY_LINE emptylines sections
                                                  ↳ 5: emptylines
                                                       ↳ 12: ε •
  Second reduce derivation
    sections
    ↳ 3: emptylines section emptylines
                            ↳ 13: EMPTY_LINE emptylines •
updating index-parse.h